Tampon applicator

ABSTRACT

A tampon applicator made with telescoping tubes, the outer tube having a series of rings convex in longitudinal section which meet, forming internal annular ridges, the inner diameter of which is slightly less than that of the undeformed portion of the same tube. The radius of the inner tube is substantially that of the annular ridges to give frictional engagement, and said inner tube has a nib of a height to snap into locking engagement with the concave valleys between said ridges. The rings in the outer tube form an enhanced finer-grip pattern in the rearward end.

United States Patent 1 2 Jaycox [451 Oct. 10, 1972 [54] TAMPON APPLICATOR FOREIGN PATENTS OR APPLICATIONS 2] Inventor: Willard J y bongmeadow, 684,290 1271952 Great Britain ..128/263 Mass.

[73] Assignee: Tampax Incorporated, New York, Primary Examiner-Charles Rosenbaum N Y Attorney-Curtis, Morris & Safford [22 Filed: Aug. 13, 1970 [57] ABSTRACT [21] Appl' 63443 A tampon applicator made with telescoping tubes, the

outer tube having a series of rings convex in longitu- [52] US. Cl ..128/263 dina] section which meet, forming internal annular [51] Int. Cl. ..A61f 15/00 ridges, the inner diameter of which is slightly less than Field Of Search that of the undeformed portion of the ame tube The radius of the inner tube is substantially that of the an- [56] References C'ted nular ridges to give frictional engagement, and said UNITED STATES PATENTS inner tube has a nib of a height to snap into locking engagement with the concave valleys between said 3,148,680 9/ 1964 Roberts et a1. ..128/263 ridges. The rings in the outer tube f an enhanced 3,347,234 10/ I967 Voss ..128/263 fi i pattern in the rearward e 3,456,640 7/1969 Schwartz ..128/263 3,575,169 4/1971 Voss ..128/263 12 Claims, 3 Drawing Figures PATENTEDHN 0 I912 3.696.812

FIG!

INVENTOR. WILLARD R. JAYCQX TAMPON APPLICATOR This invention relates to tampon applicators intended for positioning catamenial tampons.

The most common commercial form of catamenial tampon applicator which has been in use for many years consists of telescoping tubes wherein the outer tube carries the tampon in one end portion thereof and an inner tube frictionally fits in the other end positioned to abut the inner end of the tampon to project out from said other end of the outer tube. This applicator has performed well. For example, in order frictionally to maintain proper assembled relationship between the inner and outer tubes during delivery to the ultimate user, very close manufacturing tolerances have had to be maintained between the inside diameter of the outer tube and the outer diameter of the inner tube. To supplement such frictional engagement and relieve the need for extreme precision, various securing means have been employed, such as a pair of opposed pin pricks extending through both tubes causing a small interlocking deformation. Also a pin prick deformation through the outer tube has been used to deform suffi- I cient material to bear upon and frictionally engage the inner tube. Interlocking tab cutouts have also been attempted. See US. Pat. Nos. 2,489,502; 2,587,717 and 3,l48,680. These patents are representative of a continuing effort to solve these problems without unduly introducing additional problems.

The use of very smooth outer surfaces on the tubes to facilitate insertion and to improve comfort of the user may make it difficult to grab the outer tube firmly while exerting an ejecting force on the ejector tube. Several less than satisfactory solutions have been proposed, some of which are exemplified in the art cited previously. The same smooth low-friction surface which causes trouble on the exterior of the outer tube is equally troublesome on the exterior of the inner tube by reducing the effectiveness of the frictional interlock between the two tubes.

It is, therefore, an object of the present invention to provide a modification of such applicator tubes for solving these and other problems.

It is a further object to provide such a modified applicator which not only successfully solves such problems, but does so without introducing significant additional drawbacks.

It is another object to provide an effective, positive finger grip on the applicator tubes.

It is still another object to provide a reliable, positive tube interlock which successfully resists accidental disassembly during manufacture and subsequent handling prior to use yet does not introduce other undesirable drawbacks, nor interfere in any way with the ultimate use of the applicator.

In a tampon applicator constructed according to the preferred embodiment of the present invention, the outer tube of the applicator near its rearward end (opposite from the end adapted to receivev the tampon) has a series of relatively closely spaced circumferential grooves which form inwardly directed ridges on the interior having shallow valleys there between, said ridges preferably having substantially identical diameters in order to hold an inner ejector tube concentrically therein. Said inner tube advantageously has two opposing nib projections, formed thereon by outwardly directed pressure, with sufficient height to press in engagement into the valleys formed between said ridges and being positioned longitudinally at a point such that the nibs fall approximately in the middle of said series of ridges when the front end of the inner tube abuts the tampon positioned in the outer tube.

In this specification and the accompanying drawings, I have shown and described a preferred embodiment of my invention and have suggested various alternatives and modifications thereof; but it is to be understood that these are not intended to be exhaustive and that many other changes and modifications can be made within the scope of the invention. These suggestions herein are selected and included for purposes of illustration in order that others skilled in the art will more fully understand the invention and the principles thereof and will thus be enabled to modify it and embody it in a variety of forms, each as may be best suited to the conditions of a particular use.

In the drawings:

FIG. 1 is a side elevation of a preferred embodiment of the present invention.

FIG. 2 is an enlarged detail view of the device in FIG. 1, shown partially in section.

FIG. 3 is a view similar to FIG. 2 of a modified preferred embodiment.

In the illustrated preferred embodiment of the present invention, the applicator tube 10 is formed of an outer carrier tube 12 and an inner ejector (or plunger) tube 14. These tubes 12 and 14 are typically made of thin strips of paper spirally wound, with successive layers overlapping to reinforce one another. Each layer is cemented to the adjacent layers by an adhesive which is readily water soluble. Thus, after the tube has served its purpose, it can be discarded into a toilet bowl loosening the adhesive and delaminating the tubes into thin paper strips which can be readily flushed through the plumbing.

FIG. 1 shows the assembled tampon l5 and applicator 10 ready for use. The front end of the compressed catamenial tampon 15 can be seen at the right of FIG. 1 (extending from the carrier tube 12). The rear end of the same tampon 15 can be seen in FIG. 2 within the carrier tube 12 abutting the front end of the ejector tube 14.

The tampon 15 can be made according to the standard practice in the art but advantageously is formed by compression of a pad made of transversely laid long staple cotton fibers sewn down the middle with a chain of stitches trailing therefrom to form the withdrawal string 16. Such a pad with its withdrawal string is described and illustrated in a patent issued to my coworkers as U.S. Pat. No. 3,322,123, issued May 30,

The surface layer of the tubes 12 and 14 advantageously may be covered with a thin coat of a slick material usually in the form of a solid lubricant which facilitates the insertion of the applicator into the vaginal cavity without discomfort. This may be formed of polyethylene oxide or other waxy material.

The tubes 12 and 14 commonly are about three inches long. The outer tube 12, in the example illustrated in FIG. 2, has seven annular external rings 17 formed by eight grooves 18 and eight internal ridges 22. These numbers have been found most advantageous when the tube is of wound thin paper strip,

on the market. Such paper may typically be 0.015 inch thick. Depending on the tube 12 thickness, five to 12 grooves in a width (measured longitudinally of the tube) about three-eighths inch to three-quarters inch can be used and may have a depth of about 0.01 inch and a pitch of about 0.07 inch. The ridges 22 at the peaks give an inside diameter less, by 0.005 to 0.025, inch than the inside diameter of the adjacent smooth tube beyond the rings. We find that a diameter 0.015 inch less than the adjacent undeformed tube is preferable, giving substantial frictional engagement between the tubes without producing excessive resistance to ejection of the tampon.

The grooves 18 may be formed relative to ridges 22 as in FIG. 2 to assist in the formation of said ridges 22, or may be formed as in FIG. 3 to give more strength to thetube 12 by avoiding abrupt edges when using certain materials. In FIG. 3 the ridges 22 are rounded, in stead of being more sharply peaked.

With tubes having thicker walls, fewer rings should be rolled in a given width; and with thinner walls, a

larger number of rings, each narrower, should be used This grooving was found to give marked improvement. When the grooved areas are grasped between the thumb and the middle finger, a surer grip results with demonstrably less pressure required on the outer tube 12 to hold it without slipping while exerting an expulsion force with the forefinger on the free end of the ejector tube 14. This also means that less squeezing by the fingers of the inner tube 14 is experienced and therefore less expulsion pressure is required.

This grooving 18 in addition to providing a finger grip enhancement also serves to coact with raised nibs 20 to form an effective tube lock. The inward height of the ridges 22 and the depth of the valleys 24 are such as to give a uniform detention with the nibs 20. Furthermore, the approximate uniformity in height of the projection v22 gives multiple rings of support of approximately the same diameter without substantial clearance between the telescoped tubes 12 and 14. In furtherance of this, the end 19'of the outer tube 12 may be curled inwardly to the same diameter (as shown in FIG. 2).

In forming the grooving 18, the radius of curvature in successive grooves is advantageously such that the diameter of the tubing 12 measured to the rings 17 of opposite valleys 24 is a very little less than, or even the same as, the diameter of the undeformed tubing 12 beyond the grooving 18. This uniformity and positive formation of the valleys 24 assures maximum effectiveness of the interlock with minimum deformation of the tube walls by the grooving 18.

As shown by FIG. 2, in this preferred embodiment, the tube 14 has nibs 20 formed on its outer surface with convex curvature closely approximating the concave curvature of the valleys 24. Thus, in the illustrated example, the height of nib 20 is 0.01 inches above the outer diameter of the tube 14. In the broader aspects of this invention, there need be only one nib, which could be dome-shaped. However, it is preferable to give a more balanced and effective interlock by having at least two opposing nibs equally spaced circumferentially about tube 14. Again, within the broader aspects of this invention, it is possible to adopt variations in size and placement of the grooves and nibs to give functionally equivalent results with slightly different structural arrangements. For example, the pitch of the grooves (i.e., the distance between the summits or nadirs of adjacent grooves) could be substantially greater than the corresponding dimension of the nibs 20 this would still give a true interlock when two or more arealso longitudinally spaces so as to trap immediately therebetween one or more projections-22 so as to avoid longitudinal play. Thus, although such nib in one such valley might have considerable play, two such nibs in two different valleys would be positioned relative to their respective projections so as to have no such play. i

In the preferred embodiment, each of diametrically opposed nibs 20 forms a raised projection on the outer surface of the ejectortube 14 which subtends an angle of approximately circumferentially. This is particularly desirable where, as illustrated in the drawing, the grooving 18 has been interrupted in fanciful design, here to reproduce the. outline of Trademark Registration No. 585,933. With such discontinuity of the grooving 18, it is desirable to have the nibs 20 circumferentially long enough to bridge such gaps and to give effective interlocking even in-the area of such discontinuity. Note that at such discontinuities, there being no grooving 18, there usually is consequently no corresponding projections 22 on the interior of the tube 12.

The grooves 18 of the present invention represent a total departure from all prior art finger-grip concepts, which, typically, involved raised external projections of various types. The present invention permits the combination of the finger-grip feature with an effective tube interlock, where latter has the singular advantage of being self-healing if displaced. In most previous tube interlocks a portion of one interfitted tube is displaced into the other in a one-on-one relationship. Upon displacement, such one-on-one relationships are destroyed, and usually could not effectively be reestablished. With nibs and grooves as shown a nib 20 can engage a second or third valley 22 after it has been displace. Mere frictional interlocks were found to be substantially inferior.

In developing the claimed groove design, many apparent improvements failed to solve the problems. Among the many problems encountered was fracturing of the paper in the groove, spoiling the general. appearance and weakening the tube wall. This was experiences when an annular groove having a one-eighth radius of curvature was impressed inward on the outer tube 12. Giving the groove a much larger radius reduced somewhat the fracturing, but still gave a poor finger-grip quality and resulted in a slipping in the rolling of the tube during formation of the groove, which produced a glazed wrinkle and obvious weakening of the tube wall. Narrowing the surface of the roll only served to greatly increase the fracturing of the paper. Other variations were tried including a flat three-eighths inch wide shallow annular groove and multiple narrow grooves. Expulsion pressures continued to be excessive as die the fracturing of the paper.

In spite of these initial setbacks, it was ultimately found that for the given typical applicator tube construction of a given paper thickness, consistency, and quality, the eight shallow grooves over the one-half inch distance gave a good finger-grip with controllable minimal fracturing of the paper and good appearance. This particular pitch of grooves was found to be best suited to the wall thickness and deformation characteristics of typical commercial laminated paper tampon applicator tubes. It was found that at least three grooves should be formed in order to give a most effective finger-grip without unduly weakening the tube walls. On the other hand, a shorter pitch pattern having nine grooves in an approximately one-half inch zone along the tube wall may not achieve a satisfactory tube lock and may result in excessively crushing the paper.

All of the foregoing multiple grooved configurations form acceptable finger grips, but the addition of the tube lock by the incorporation of the nibs makes the final product better adapted for transport and ultimate application. It is a more secure lock.

Thus, this unique combination of fomiing shallow multiple grooves in a manner to give an effective finger-grip and internal tube lock has many advantages over the prior art. The two nibs 20 externally raised on opposite sides of the internal tube 14 not only give an effective interlock, but also permits a relaxation of manufacturing dimensional tolerances of the tubes and further creates a continuously positive tube lock. These nibs are advantageously located on the ejector tube 14 in an end zone one-eighth to three-fourths inch from the end of the tube. In the preferred example above described they are one-half inch from the end. The nibs shown in the preferred embodiment extend over 90 around the circumference of this tube but any extent from 50l 20 can be used with satisfaction.

The over-all diameter of the tube 14 on opposite sides is increased by about 0.005 to 0.03 inch when the nibs are included. In the preferred example we have found an increase of 0.02 inch best. These diameters are taken from the apogee of the nib on one side to the corresponding point on the opposite nib and this distance is compared with a corresponding measurement of a part of the tube where there are no projections or other deformation.

As was indicated previously, accidental displacement of the tube lock does not ordinarily destroy its effectiveness. Longitudinal displacement of one-sixteenth of an inch was sufficient to destroy the pin prick" tube interlock, while with the present invention displacement of one-fourth of an inch (or more if additional grooves are added) can be tolerated while still preserving effectiveness of the lock. The increase in finger engagement provided by the grooves 18, reduces the radia1 pressure necessary for gripping the tube, and thus reduces the necessary expulsion pressure, which permits more effective tube lock by the nibs 20 coacting with the projections 22, which solves many problems in the assembly and subsequent handling of the tampon and its applicator during production, shipping and use by the ultimate user.

Since there is no interlocking of the laminations such as was often encountered in prior art tube lock methods, the present invention, rather than hindering delamination when discarded, tends to facilitate it.

Although I have shown and described a preferred embodimentof this invention, it should be understood that variations are possible within its scope. Thus, the applicator tubes may be made of other sheet material instead of paper, e.g., plastic, or the tubes may be molded of plastic with the ridges and grooves. Instead of rolling the grooves, ridges and nibs, etc., into the wall of the tubes, they may be molded into it by pressing it in a mold either with or without heat.

I claim:

1. A tampon applicator comprising an outer tube adapted to contain a tampon in the forward end thereof, an inner tampon-ejecting tube fitted within said outer tube, said outer tube having in the rearward portion thereof a series of at least four adjacent substantially circumferential internal ridges with at least three shallow, equally-sized, valleys alternating therebetween and with similarly positioned grooves formed externally in a finger-grip pattern, said inner tube having at least one raised nib being of substantially the same longitudinal curvature and size of said valleys in order to frictionally interlock within any one of said valleys to inhibit relative longitudinal movement of said applicator tubes and being of a transverse circumferential extent of less than a total of 240, the outer diameter of said inner tube being sufficiently smaller than the inner diameter of said outer tube so as to form a loose fit therebetween, said internal ridges all having the same minimum inside diameter which is approximately the same as the outside diameter of said inner tube whereby to give a snug fit between said tubes with a controlled range of expulsion pressure.

2. An applicator as claimed in claim 1 wherein said grooves and ridges are substantially continuous closed circles and are respectively equally spaced from one another.

3. An applicator as claimed in claim 2 wherein said external grooves are formed into said outer tube correspondingly opposite said internal ridges between and said external rings are formed correspondingly opposite said internal valleys.

4. An applicator as claimed in claim 2 wherein the inner diameter of said outer tube is substantially th same as the maximum diameter of said valleys.

5. An applicator as claimed in claim 2 wherein said inner tube has at least two nibs, widely spaced circumferentially.

6. An applicator as claimed in claim 5 wherein said nibs and the valleys between said ridges are formed with corresponding curvature to snuggly interfit.

7. An applicator as claimed in claim 5 wherein said ridges are circumferentially interrupted only by an extent less than the circumferential extent of said nibs.

8. An applicator as claimed in claim 2 wherein said outer tube is formed from paper and said grooves and ridges are impressed thereon.

9. An applicator as claimed in claim 8 wherein said rings and ridges have a substantially greater radius of curvature than their corresponding grooves and valleys.

10. An applicator as claimed in claim 8 wherein said outer tube is formed of spiral laminated paper strip wound in overlapped spirals and bonded with a waterreleasable adhesive.

grooves and ridges are each eight in number and are formed in anapproximately one-half inch axial extent with groove depths, ridge and nib heights of approxi-- mately 0.01 inches. 

1. A tampon applicator comprising an outer tube adapted to contain a tampon in the forward end thereof, an inner tamponejecting tube fitted within said outer tube, said outer tube having in the rearward portion thereof a series of at least four adjacent substantially circumferential internal ridges with at least three shallow, equally-sized, valleys alternating therebetween and with similarly positioned grooves formed externally in a finger-grip pattern, said inner tube having at least one raised nib being of substantially the same longitudinal curvature and size of said valleys in order to frictionally interlock within any one of said valleys to inhibit relative longitudinal movement of said applicator tubes and being of a transverse circumferential extent of less than a total of 240*, the outer diameter of said inner tube being sufficiently smaller than the inner diameter of said outer tube so as to form a loose fit therebetween, said internal ridges all having the same minimum inside diameter which is approximately the same as the outside diameter of said inner tube whereby to give a snug fit between said tubes with a controlled range of expulsion pressure.
 2. An applicator as claimed in claim 1 wherein said grooves and ridges are substantially continuous closed circles and are respectively equally spaced from one another.
 3. An applicator as claimed in claim 2 wherein said external grooves are formed into said outer tube correspondingly opposite said internal ridges between and said external rings are formed correspondingly opposite said internal vAlleys.
 4. An applicator as claimed in claim 2 wherein the inner diameter of said outer tube is substantially the same as the maximum diameter of said valleys.
 5. An applicator as claimed in claim 2 wherein said inner tube has at least two nibs, widely spaced circumferentially.
 6. An applicator as claimed in claim 5 wherein said nibs and the valleys between said ridges are formed with corresponding curvature to snuggly interfit.
 7. An applicator as claimed in claim 5 wherein said ridges are circumferentially interrupted only by an extent less than the circumferential extent of said nibs.
 8. An applicator as claimed in claim 2 wherein said outer tube is formed from paper and said grooves and ridges are impressed thereon.
 9. An applicator as claimed in claim 8 wherein said rings and ridges have a substantially greater radius of curvature than their corresponding grooves and valleys.
 10. An applicator as claimed in claim 8 wherein said outer tube is formed of spiral laminated paper strip wound in overlapped spirals and bonded with a water-releasable adhesive.
 11. An applicator as claimed in claim 8 wherein said grooves and ridges are formed in the rearward quarter of said outer tube with from three to nine grooves formed to raise corresponding ridges which latter are effectively spaced to trap said nibs.
 12. An applicator as claimed in claim 9 wherein said grooves and ridges are each eight in number and are formed in an approximately one-half inch axial extent with groove depths, ridge and nib heights of approximately 0.01 inches. 